STRYMON was a River-God of Edonia in Thrake (modern-day northern Greece).

The Strymon River flowed into the Aegean Sea between the Khalkidike peninsular and the island of Thasos. The major neighbouring rivers were the Nestos to the east, and Axios in the west. The small Brykhon stream, to the west before the Axios, was also personified.

ENCYCLOPEDIA

STRYMON (Strumôn),a son of Oceanus and Tethys, was a river god of Thrace, and is called a king of Thrace. (Hes. Theog. 339 ; Conon.Narr. 4 ; Anton. Lib. 21.) By Euterpe or Calliope, he became the father of Rhesus (Apollod. i. 3. § 4 ; Eurip. Rhes. 347), and by Neaera of Euadne. (Apollod. ii. 1. § 2.)

Pseudo-Apollodorus, Bibliotheca 2. 3 :
"Zeus [had] a son Argos . . . He got the rule and named the Peloponnesos Argos after himself. He married Euadne, the daughter of Strymon and Neaira."

Pseudo-Apollodorus, Bibliotheca 2. 112 :
"Herakles blamed the Strymon river for his difficulty in gathering the cattle [of Geryon, which had wandered off in Thrake,] and, where it had previously been a navigable stream, he made it unnavigable by filling it in with rocks."